Automatic stop and tempo control for talking-machines.



J. A. DAVIS.

AUTOMATIC STOP AND TEMPO CONTROL FOR TALKING MACHINES.

APPLICATION FILED AUG.28. 1916.

1 ,2? 6, 1 82 Patented Aug. 20, 1918,

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JOHN A. DAVIS, OF BOSTON, MASSACHUSETTS.

AUTOMATIC STOP AND TEMPO CONTROL FOR TALKING-MACHINES.

Specification of Letters Patent.

Patented Aug. 20, 1918.

Application filed August 28, 1916. Serial No. 117,150.

To all whom it may concern:

Be it known that I, J OHN A. DAVIS, a citizen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have invented a certain new and useful Improvement in Automatic Stops and Tempo Controls for Talking-Machines, of which the to ,talking machines in which the record is a disk which is rotated by a suitable mechanism acting on the record through a spindle and turn table. It is particularly adapted to electrically driven talking machines, but

I do not limit myself to this application of my invention.

The automatic stop described herein is characterized by the fact that the motor is set in motion by the actuation of a small rod located centrally of the spindle and movable therein. This rod also serves to operate the tempo control. This feature I believe to be altogether novel and one which has certain very important advantages hereinafter more fully explained.

The invention will be fully understood from the following description when taken in connection with the accompanying drawings and the novel features thereof will be pointed out and clearly defined in the claims at the close of this specification.

In the drawings, Figure 1 is a vertical section of the machine embodying my invention only the sound box or speaker carried by the customary type of tone arm and 7 part of the turn table and operating mechanism being shown.

Fig. 2 is a section on line 2-2 of Fig. 1. Fig. 3 is a section on line 3 '3 of Fig. 1.

Having reference to the drawings at A is shown the sound box, at B the needle, at C the main drive shaft and at D the pulley for the main drive shaft. These parts are of the ordinary construction and do not need to be described in detail. At 11 is shown the turn table and at 12 the record.

,On the sound box A is secured a bracket is on the horizontal portion of which is located an adjustable eccentric contact member 15 which may be secured in any position of adjustment by a thumb screw 16. The edge of the eccentric contact member is beveled as shown at a. The spindle on which the turn table 11 is mounted is shown at 17 and is tubular being secured to the member 18 of a set of ball bearings, the balls being shown at 19. At 20 is shown the Worm wheel withwhich the worm 21 on the main drive shaft C meshes. I Located within the tubularspindle 17 is a stationary sleeve 22 by means ofwhich the tempo control is operated as will be later described and iiiside of this sleeve 22 is a rod 23 by means of which the automatic stop is operated. The upper end of the rod 23 is provided with a contact button 2%, the upper part of which is conical or rounded. The lower end of the rod 23 passes down into a switch box 25. At 26 is shown a movable switch member which is perforated as shown in Fig. 3 to allow the lower end of the stop rod 23 to pass through it, there being two buttons 27 and 28 above and below the movable switch member 26. At 29, 29 are shown two springs one end of each being secured to the movable switch member 26 and the other end secured at the point 30 to a fixed part of the switch box, this point being beyond the pivot 31 on which the mov a'ble switch member swings. At 32 is shown a contact point properly located to contact with the switch 26 at certain times. It will be seen that this construction produces a very delicate switch and that when the contact member 26 is moved into a position above or below the pivot 31 the springs 29 will tend to pull the switch member up or down as the case may be. p

The upper end of the inside sleeve 22 is slotted asshown at 33 to permit vertical movement of the pin 34: secured to the stop rod 23. This permits the stop rod to be lifted up or pushed down and also permits the sleeve 22 to be rotated by turning the button 24. This construction is for the purpose of operating the tempo control. At the lower end of the sleeve 22 is located an eccentrio 35 which rests against one arm 36 of the bell crank pivoted at 37 to the frame of the machine. The other arm 38 carries a felt pad 39 which bears against the friction disk 40 forming part of the governor 50. It will be seen that by changing the position of the bell crank lever which is effected by rotating the button 24 the felt friction member 89 will be caused to bear more or less firmly against the friction disk 40 and will increase or decrease the load on the driving mechanism thereby correspondingly affecting the speed of the machine and varying the tempo control. 7

The stop mechanism is operated in the following manner. The needle B is set in the last thread of the record and the eccentric 15 adjusted until its edge just touches the button 24. The eccentric is then fixed in this position of adjustment. The needle is then placed in the first thread of the record and the button 24: pulled up thereby lifting the'movable switch member 26 into contact with the contact member 32. The adjustment of the eccentric 15 as just described, takes care of any variation in the width of the effective portion of the record. By this means the stop mechanism can be adjusted so that it will stop the machine when the end of the record is reached regardless of the total Width of the effective portion of the record. As the record is played the contact member carried by the stop arm gradually approaches the button 24:. Just as the end of the record is reached the inclined surface a on the under side of the eccentric contact member 15 rides onto the rounded head of the button 24 and pushes it down sufiiciently to carry the switch member 26 by the horizontal line passing through its pivot. As soon as this occurs the springs complete the movement thereby breaking the current which operates the machine. The switch described is so delicate that the very slight pressure exerted by the sound box attached to and carried by the tone arm is sufficient to actuate it and stop the machine.

The mechanism described which is actuated by mechanism located centrally of the disk, and forming part of the spindle on which the record revolves is advantageous, because its practical operation is the same regardless of the size of the record, the width of the effective portion of the record, the size of the turn table, the length of the tone arm, type of sound box, size or type of cabinet, or in fact an other existing condition or measurement ound in any talking machine. In other words, it is immediately adaptable to any talking machine which plays a disk record. It also makes possible a quick and simple adjustment which makes certain that the stop mechanism will act at the time just when the end of the record is reached regardless of the length of the record. The location of the tempo control mechanism centrally of the disk is also very desirable because it makes it a part of the single self contained Whole which can be made separate from the rest of the machine so that an electrical driving unit is produced which can be substituted for a hand operated sprin motor in a hand operated machine and w iich includes the stop mechanism and tempo control.

\Vhat I claim is:

1. A stop mechanism for a disk record sound reproducing machine, comprising a longitudinally movable spindle mounted coaxially with the record, a contact member mounted on the lower end of said spindle, a second contact member with which said contact carried by the spindle is adapted to be engaged and disengaged by the movement of the spindle, means controlled by said two contact members whereby when said two contact members are in contact with each other, the turn table of the machine will be rotated, and whereby when said contact members are separated, the rotation will be a stopped, and stop actuating means connected with the sound member, which is so positioned that when the needle has reached a predetermined point in the record, said stop actuating means will engage said movable spindle and actuate the same to disengage the contact member carried at its lower end from the said cooperating contact and thereby stop the rotation of the table.

2., In combination with a disk record sound reproducing machine, stop mechanism for the record comprising a longitudinally movable spindle mounted co-axially with the record, a contact'member connected with said spindle, a second contact member with which said contact member which is connected with the spindle is adapted to be engaged and disengaged by the movement of the spindle, means controlled by the engagement of the two contact members with each other to rotate the record, and controlled by the disengagement of said contact members to stop the rotation of the record, and a stop actuating member connected with the sound member of the machine, which'is so positioned that it will engage said movable spindle at a predetermined point in the rotation of the record, and actuate said spindle to disengage the contact member carried thereby from the other contact member with which it is engaged, and thereby stop the rotation of the record.

3. In combination with a disk record sound reproducing machine, stop mechanism for the record comprising a longitudinally movable spindle mounted co-axially with the record, a contact member connected with said spindle, a second contact member with which said contact member which is connected with the spindle is adapted to be engaged and disengaged by the movement of the spindle, means controlled by the engagement of the two contact members'with each other to rotate the. record and controlled by the disengagement of said contact members to stop the rotation of the record, a stop actuating member connected with the sound member of the machine which is so positioned that it will engage said movable spindle at a predetermined point in the rotation of the record, and actuate said spindle to disengage the contact member carried thereby from the other contact member with which it is engaged, and thereby stop the rotation of the record, and means for adjusting the position of said step actuating member whereby the predetermined time for engagement with said spindle may be varied.

4. In a stop mechanism for talking machines, the combination of the record, a contact member at the axis of rotation, which is operatively connected to the stop mechanism, a contact member on the tone arm member, and means for adjusting the position of said second mentioned contact memher lengthwise of the path of movement of the tone arm to compensate for difiering lengths of records.

- 5. The improved stop mechanism and tempo control comprising a contact member on the sound box of the machine a movably mounted contact member at the axis of rotation, a spindle secured to the second contact member, a switch operated by said spindle, a sleeve operatively connected to the spindle and carrying an eccentric, a disk 011 the drive shaft of the machine and a bell crank lever operated by said eccentric and carrying a brake member which contacts with said disk.

In testimony whereof I afiix my signature, in presence of two witnesses.

JOHN A. DAVIS. Witnesses:

CAMERON MACLEOD, MAZY McOULLocH.

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